<Emphasis Type="Italic">In vitro</Emphasis> Enhancement of Lactate Esters on the Percutaneous Penetration of Drugs with Different Lipophilicity

Lactate esters are widely used as food additives, perfume materials, medicine additives, and personal care products. The objective of this work was to investigate the effect of a series of lactate esters as penetration enhancers on the in vitro skin permeation of four drugs with different physicochemical properties, including ibuprofen, salicylic acid, dexamethasone and 5-fluorouracil. The saturated donor solutions of the evaluated drugs in propylene glycol were used in order to keep a constant driving force with maximum thermodynamic activity. The permeability coefficient (K _p), skin concentration of drugs (SC), and lag time (T), as well as the enhancement ratios for K _p and SC were recorded. All results indicated that lactate esters can exert a significant influence on the transdermal delivery of the model drugs and there is a structure-activity relationship between the tested lactate esters and their enhancement effects. The results also suggested that the lactate esters with the chain length of fatty alcohol moieties of 10–12 are more effective enhancers. Furthermore, the enhancement effect of lactate esters increases with a decrease of the drug lipophilicity, which suggests that they may be more efficient at enhancing the penetration of hydrophilic drugs than lipophilic drugs. The influence of the concentration of lactate esters was evaluated and the optimal concentration is in the range of 5∼10 wt.%. In sum, lactate esters as a penetration enhancer for some drugs are of interest for transdermal administration when the safety of penetration enhancers is a prime consideration.     

Preparation of capacitor’s electrode from sunflower seed shell

Series of nanoporous carbons are prepared from sunflower seed shell (SSS) by two different strategies and used as electrode material for electrochemical double-layer capacitor (EDLC). The surface area and pore-structure of the nanoporous carbons are characterized intensively using N₂ adsorption technique. The results show that the pore-structure of the carbons is closely related to activation temperature and dosage of KOH. Electrochemical measurements show that the carbons made by impregnation-activation process have better capacitive behavior and higher capacitance retention ratio at high drain current than the carbons made by carbonization-activation process, which is due to that there are abundant macroscopic pores and less interior micropore surface in the texture of the former. More importantly, the capacitive performances of these carbons are much better than ordered mesoporous carbons and commercial wood-based active carbon, thus highlighting the success of preparing high performance electrode material for EDLC from SSS.     

烟草抗黑胫病突变体的细胞筛选

经实验我们成功地建立了在细胞水平上筛选烟草抗黑胫病突变体的筛选体系。该体系的主要内容为:γ-射线500—2000拉德诱变高度感病品种的花药后用50—80％的黑胫病菌粗毒素为选择压力,筛选出抗毒素花粉植株,用离体叶片法测定选出抗病植株,再从后代鉴定中选出抗病性能够稳定遗传的突变系。γ-射线及高浓度毒素处理均能得到抗病植株。选自感病品种的花粉植株中约有9—50％是真正抗病的。这些抗病植株中有一部分的抗病性能够稳定遗传。用该法已从感病优质品种小黄金1025及乔庄黑苗中选出6个突变系。并自N.C.628(抗)×小黄金1025(感)及N.C.628(抗)×庆胜2号(感)的F_1花粉植株中选出4个抗病系。所有的抗病系经3—4代后均表现出稳定抗性。其中一个突变体(R400)的抗性似由不完全显性多基因控制。     

热应激时大鼠肺组织中β—肾上腺素受体的变化与膜磷...

To explore the relationship between the change of beta-adrenoceptor and the metabolism of phospholipids in lung tissue from acute heat stressed rats, the Bmax of beta-adrenoceptors, the activity of phospholipase A2 (PLA2), the content of phosphatidylcholine (PC) and phosphatidylserine (PS), and membrane fluidity in lung tissue of normal and heat stressed rats were investigated. The relevant parameter values mentioned above were 479 +/- 94 fmol/mg protein, 78.5 +/- 8.2 U, 53.5 +/- 1.7 mg/g.wet. w. and 425.1 +/- 68.1 micrograms/g.wet. w. respectively. Whereas in the heat stressed rats with rectal temperature raised to 42 degrees C for 15 min, the Bmax of beta-adrenoceptor was decreased by 43% (P less than 0.01), the activity of PLA2 increased by 83% (P less than 0.01), the contents of PC and PS decreased by 50% and 47% (P less than 0.01) respectively. A lower membrane fluidity in lung tissue for heat stressed rats was also demonstrated. The results suggest that the decreased binding sites of beta-adrenoceptor in lung tissue of rat during hyperthermia may be contributed to the activation of PLA2, which then accelerated the catabolism of phospholipids such as PC and PS in the cell plasma membrane, with a consequent alteration of membrane fluidity.     

Auxin levels and auxin binding protein availability inrolB transformedBeta vulgaris cells

The final biological effect of auxin depends both on free auxin levels and on auxin perception capacity.RolB transformedBeta vulgaris L. hairy roots provide a system for studying both factors. Highly purified plasma membrane fractions were prepared with aqueous two-phase partitioning. Individual hairy root clones were assessed for the binding activities of plasma membrane-bound auxin binding proteins and for their free intracellular indole-3-acetic acid levels. The presence of a high affinity auxin binding protein with a dissociation constant of 9.07 x 10^?7 M was detected in the plasma membrane fractions isolated from non-transformed seedling roots and the six clones ofrolB transformed hairy roots. However, the levels of specific IAA binding considerably varied among different hairy root clones and between transformed and non-transformed roots. The levels of the detectable polypeptide in immunoblotting with an antibody against maize 22-kD auxin binding protein subunit were in good agreement to the levels that were detected in auxin binding assays. Differences in the indole-3-acetic acid levels were found between transformed and non-transformed roots and also between different transformed hairy root clones. A negative correlation was observed between free intracellular IAA levels and its specific binding to the plasma membrane-bound auxin binding proteins. A latency study indicated that the binding site for auxin may be located on the exterior face of the plasma membrane     

In vitro viability and ultrastructural changes in bovine oocytes treated with a vitrification solution

Abattoir-derived oocytes were exposed to a concentrated cryoprotectant solution (DAP213: 2 M DMSO, 1 M acetamide, 3 M propanediol, and 10% FCS in TCM199) for 1.5 or 5 min at the germinal vesicle (GV) stage or after maturation in vitro (IVM). Their viability was assessed by in vitro fertilization (IVF) and culture (IVC) to blastocysts. To investigate the effect of DAP213 on the ultrastructure, GV and IVM oocytes were processed for transmission electron microscopy (TEM) before (control) or after exposure to the cryoprotectant. DAP213 induced profound ultrastructural modifications to the microvilli and mitochondria, resulted in large vesicle formation, and, most significantly, caused the premature release of the cortical granules (CG). In IVM oocytes exposed to the cryoproteclant for 5 min, exocytosis of CG into the perivitelline space was common and the IVF rate was reduced (P <.05). After exposure for 5 min, GV oocytes displayed clusters of CG comparable to controls, but after IVM-IVF, polyspermy rate was increased (P <.05). Furthermore, treated GV oocytes showed a reduced rate of cleavage and blastocyst formation and an increased percentage of oocytes exhibiting alterations in organelles, whereas the viability and ultrastructure of IVM oocytes treated for 1.5 min was not different from controls. These observations demonstrate that (1) cortical granule kinetics is one of the key elements controlling fertilizability of bovine oocytes treated with cryoprotectant, and (2) GV oocytes are more sensitive to the cryoprotectant than those that have already been matured in vitro.     

Direct interaction of v-Src with the focal adhesion kinase mediated by the Src SH2 domain.

The recently described focal adhesion kinase (FAK) has been implicated in signal transduction pathways initiated by cell adhesion receptor integrins and by neuropeptide growth factors. To examine the mechanisms by which FAK relays signals from the membrane to the cell interior, we carried out a series of experiments to detect potential FAK interactions with proteins containing Src homology 2 (SH2) domains that are important intracellular signaling molecules. Using v-Src-transformed NIH3T3 cells, we showed that FAK was present in the immune-complex precipitated by anti-Src antibody, suggesting potential interaction of FAK with v-Src in vivo. We also showed potentially direct interaction of FAK with v-Src in vivo using the yeast two-hybrid system. Using recombinant FAK expressed in insect cells and bacterial fusion proteins containing Src SH2 domains, we showed direct binding of FAK to the Src SH2 domain but not to the SH3 domain in vitro. A kinase-defective mutant of FAK, which is not autophosphorylated, did not interact with the Src SH2 domain under the same conditions, suggesting the involvement of the FAK autophosphorylation sites. Treatment of FAK with a protein-tyrosine phosphatase decreased its binding to the Src SH2 domain, whereas autophosphorylation in vitro increased its binding. These results confirm the importance of FAK autophosphorylation sites in its interaction with SH2 domain-containing proteins. Taken together, these results suggest that FAK may mediate signal transduction events initiated on the cell surface by kinase activation and autophosphorylation that result in its binding to other key intracellular signaling molecules.     

GPX－abzyme对受XO／HX系统损伤的心肌线粒体的保护作用

探讨了研制的具有谷胱甘肽过氧化物酶活力的含硒抗体酶（ＧＰＸ－ａｂｚｙｍｅ）对于受损心肌线粒体的保护作用,利用牛的心肌线粒体为实验材料,通过线粒体的膨胀度、脂质过氧化物含量、ＣＣＯ活力变化及电镜观察等几个方面证明ＧＰＸ－ａｂｚｙｍｅ能抵抗ＸＯ／ＨＸ系统产生的自由基的损伤作用,ＥＳＲ研究也表明ＧＰＸ－ａｂｚｙｍｅ能明显降低ＸＯ／ＨＸ损伤系统中的自由基含量。     

Induction of a Nerve Growth Factor-Sensitive Kinase that Phosphorylates the DNA-Binding Domain of the Orphan Nuclear Receptor NGFI-B

Abstract: Nerve growth factor (NGF) induces the synthesis and the phosphorylation of the orphan nuclear receptor NGFI-B in PC12 cells. Previous work has shown that phosphorylation, by protein kinase A, of a specific serine in the DNA-binding domain inhibits its binding to the NGFI-B response element. Also, cytoplasmic extracts from PC12 cells phosphorylate this serine, and phosphorylation is greater in extracts from cells treated with NGF. The present work describes the induction, identification, and partial purification of a kinase (termed NGFI-B kinase I) from PC12 cell extracts that catalyzes this phosphorylation. Phosphorylation of the DNA-binding domain with this purified preparation inhibits its binding to the NGFI-B response element. The kinase is rapidly activated by treatment of the cells with NGF, and the activation lasts for at least several hours. It also is activated by fibroblast growth factor and epidermal growth factor (EGF), but the activation by EGF is quite transient. The kinase requires Mg²⁺ but will use Mn²⁺. The molecular mass of the kinase is 95–100 kDa, and it is different from protein kinase A, Fos kinase, or pp90 ^rsk . Comparison with a partially purified preparation of cyclic AMP response element-binding protein kinase, however, indicates that the two are either very similar or identical.     

Se和V_E与克山病

以克山病病区粮配成基础饲料,另在基础饲料中分别补充Ｓｅ或ＶＥ,或Ｓｅ＋ＶＥ喂养大鼠,在细胞及亚细胞水平上以Ｃａ代谢为主研究并比较了Ｓｅ和ＶＥ在克山病病因中的作用。测量了心肌细胞和心肌线粒体的Ｃａ代谢及有关指标、心肌线粒体能量转换功能及心肌组织自由基含量。结果表明,在低Ｓｅ病区粮中补充Ｓｅ或ＶＥ均能在一定程度上预防病区粮中致病因素对心肌细胞及线粒体的损伤;并且补充Ｓｅ或ＶＥ均能使心肌组织中自由基含量减少。提示Ｓｅ和ＶＥ是通过清除体内过量自由基预防细胞和线粒体的损伤的。但值得注意的是,实验中所用病区粮ＶＥ含量不低于甚至高于非病区对照粮,在低Ｓｅ情况下,所补ＶＥ的量需要相当大（如本实验中补充２００μｇ／ｇ）才能较明显地预防心肌细胞和心肌线粒体的损伤。通过对这些结果的分析,进一步肯定低Ｓｅ是克山病形成的重要因素之一。